A non-linear controller for single-phase DC-AC power converter using in the grid-connected photovoltaic

摘要

A photovoltaic system connected to the grid is constituted by two main parts: a solar cell and a power converter DC-AC. The impedance adaptation between the two parties is a technological problem that essentially means the transfer of maximum power of PV generator to the grid. In this paper, a new technique for nonlinear control of power converter DC-AC is presented. This converter is built on two stages: a DC-DC stage and a DC-AC stage. The two blocks are bound by a DC voltage intermediate bus. The control objective is threefold: i) control the input voltage of the converter to find the MPP (maximum power point), ii) regulating the DC bus voltage, iii) generate a sinusoidal current at industrial frequency that will be injected into the network with a power factor near unity. The synthesis of controllers was performed using the technique of backstepping nonlinear control. A detailed analysis of the stability control system is presented. The performance of controllers has been validated by numerical simulation in MATLAB / SIMULINK.